Electrical make-and-break device.



E. T. SHAW. MAKE AND BREAK DEVICE.

ELECTRlCAL APPLICATION FILED MA 1,236,989. Patented Aug. 14, 1917.

06 I2 [0 I: .jl'dwnrd 1 5/1011).

pc I

KTED I STATES AT ED'WAE'D T. SHAW, OF PITTSFIELD, MASSACHUSETTS, ASSIGNOR TQ PITiTSEiELD SPABI i COIL COMPANY, OF PITTSFIELD, MASSACHUSETTS" A CORPORATION OF MASSACHU- SETTS.

ELECTRICAL MAKE-AND-BREAE DEVICE.

Specification of Letters Patent.

Application filed March 30, 1916. Serial No. 87,706.

To (425 whom it may concern Be it known that I, EDWARD T. SHAW, a

citizen of the-United States of America, re-

siding in the city of Pittsfield, county of 13 'l'shire,.and State of Massachusetts, have invented certain new and useful Improvements in Electrical lvlake-and-Break Devices, of which the following is a specification.

This invention relates to improvements in make and break devices for electrical ignition systems for internal combustion engines. These devices are connected in the primary circuit of the system and an object of the invention is to provide a mechanism that will positively close and open the contactpoints of the make and break device directly from the cam member. Heretotore it has been the common practice to operate the contact points through some intermediate mechanism that is located between the timer cam and the part or parts on which the contact points are located.

A further object is to so shape the timer cam thatthe engine may be permitted to operate in either direction, as desired. A :iurtl or object is to so connect the parts-of the c Yap composing the device as to permit readily separated and placed over a i ia't't and then retain the two parts of sing: securely fastened together. it farther object of the invention is to provide adjustinq' devices for the springs on wliicl'i the contact points are independently r mounted.

Further objects and nature of the invention will be fully set forth in the body of the specification and particularly pointed out in the claims.

Referring briefly to the drawings:

l i ure l is a side elevational view of the device, showing" the internal construction and arrangement or the device with the contact points closed;

i F 2 is a transverse sectional view taken in a plane on line 22 of Fig. 1, looking 1n the direction of the arrows, and showing the manner of mounting the lower leaf contact supportingspring.

Referring to the drawings in detail: 1 and 2 designate the two separable parts of the iuelosing casing. the pivotal connection for the parts being shown at 3 and the line of separation being indicated by the nu merais l. 5. 6. and 7. 8 designates a screw for securing the part 2 to the arm 9 of the part 1. The timer shaftis indicated at 10, and the timer cam at 105 This cam is formed with the elevated'portions l2 and the flat or lower portions 13, saidportions being arranged so as to correctly time the make and break device to correspond with the point in the cycle when ignition should occur. It should be particularly observed that the length of the surfaces 1? 0n opposite sides of the elevated portions 12 make equal angles with the radial linesHwhich pass through the apices of the parts 12 in order that it may be used on an engine operating the timer in either direction.

The platinum springs or levers 17 and 18. The spring 17; is secured to the slitted screw pivotally connected to thecasing 1; its outer end is engaged by a'screw 20 having a lock nut 21. This screw is for the purpose of adjusting the tension and point of'and duration of contact of the spring 17 with the cam 10 for the reason that the more this spring is bent or placed under stress the longer or shorter will be the period ofcontact between the cam and spring. The spring- 18, which carries the insulated piece 2,;is also'adjustable by means of the setscrew 22 and lock nut 23 for the same reason as stated in connection with the adj ustment of the spring 17. 2% indicates a bolt which passes through the spring 18 and angular shaped bracket 25. This bolt'serve s as'one of the terminals to which one end of the primary wires-is connected. When the cam 10 'is rotated, say in the contra-clockwise direction of the arrow 26, the elevations 12 will-act to close the contacts 15 and 16, as shown in 'piece of insulation 2' at this momentfdoes not engage the flat or lower surface 13. As the cam 10' moves forward the piece of in sulation 2 will be engaged by the "elevated part causing the contacts 15 and .16 to be positively opened, as the cam continues to rotate, first the spring 17 then the insulation 2 will drop onto-the depressed portion of the cam, the succeeding elevated-part 12 will engage the spring 17 and positively close the contacts for the next cylinder. The cam 10, therefore, serves the double purpose of posi. tively and directly opening and closing the contact terminals. It should be observed that correct timing of the device requires that the extent of the elevation 12 be broad enough to support both springs at the same Fig. 1; the

19' which is time in order that the contacts shall be closed until the elevated portion strikes the insulation 2. If this portion of the cam 10 is not so constructed then the spring 17, when it drops into the depressed portion of the cam, will open the contact before the raised portion strikes the insulated part 2, otherwise an angular and indefinite timing will occur. The set screws 20 and 22, it will be seen; serve the purpose of independently varying the tension and point of contact and length of duration of the contact of the springs 17 and 18 with the cam 10' and consequently the time that the points are closed. The adjustment of the springs 17 and. 18 therefore changes the duration period of the time of closing of the contacts. In order to advance or retard the time that the contacts areoperated the usual connection is made with the arm 9 by means of-the rod 26 engaging the opening 9' whereby the make and break device, as a whole, may be oscillated about the shaft 10.

The elevations and depressions on the cam 10', it will be observed, are symmetrically arranged around its outer surface, whereby the cam may operate in either direction.

The casing is made symmetrical about its center line 27 shown in'Fig. 2, so that when turned over the springs 17-18 will assume their proper position for operation of the engine in the reverse direction.

It will also be observed that by reason of the casing being separable access to the contact points and springs 17 and 18 is readily obtained for repairs,- adjustment, or installation of the various parts.

It should be particularly observed that the piece of insulation 2 serves to insulate the lever 18 from the cam in order to avoid or prevent a' short circuit from points 15 to 16 through the cam, while said points are held open. This is an important feature as other means must be employed to accomplish the same purpose if piece 2 What I claim is: 1. A timer and make and break device having in combination, a casing, contact oints, springs for independently supportwere not used.

mg the points and located on the casing, a

cam having symmetrically arranged elevations and depressions for directly engaging the springs for causing the positive closing and opening of the contact points.

2. A make and break device for opening and closing the primary circuit of an electrical ignition system or internal combustion engines, comprising a separable casing, an electrical contact point mounted on each of the separable parts of the casing, means for adjusting each contact point, a cam for operating the points, one of the contact points from the cam.

-ing each of the point, said cam engaging the 'tlvely closing and opening said points, means means for insulating 3. An electrical make and break device comprising a rotatable cam, contact points,

7 each mounted on a spring arm or lever, set

the contact points.

4:. An electrical make and break device comprising a rotatable cam, contact points, each mounted on a spring lever, one of the levers having a piece of insulating material secured thereto and engaging the rotatable cam, and means for independently adjustlevers on which the contact points are carried.

5. An electrical make and break and timer device comprising a casing, a cam having symmetrically arranged elevations and depressions on its periphery, levers engaging the periphery of the cam and carrying contact points, said cam and levers being so constructed as to permit assembly for rotation and operation of the levers in either direction, one of the levers being insulated from the cam, said cam serving to directly engage the levers and to positively close and open the contacts, as described.

6. The combination with a rotatable cam, of contact points, elastic levers for supporting the points, independent devices for adjusting said levers, one of the levers having a piece of insulation for engaging the cam, a separable casing for supporting the levers and opening on a line between the levers to permit ready access to said points, as described.

7. An electrical make and break device comprising in combination, a cam having elevated portion and lower surfaces that are located below said portion, electrical contacts, a lever to support each contact, said cam serving to positively and directly engage the levers to close and open said contacts, means for independently adjusting each lever and contact,'and means to insulate one lever from the cam. v

8. An electrical make-'andbreak device Comprising in combination, a rotatably mounted cam formed with equally spaced elevations and depressions, a casing, a pair of spring levers each carrying a contact levers for posifor placing each lever under a varying stress to vary the duration of closure of the points, and a movable casing for supporting said levers for advancing or retarding the time of closing said contacts.

EDl/VARD T. SHAW 

